Batman and Batkid exit their cave at Union Square on Nov. 15 in San Francisco. The Greater Bay Area Make-A-Wish Foundation turned the city into Gotham City for Miles Scott, 5, by creating a day-long event bringing to life his wish to be a Batkid. Ramin Talaie, Getty Images

Miles Scott, dressed as Batkid, right, walks with Batman before saving a damsel in distress in San Francisco. Jeff Chiu, AP

The Batmobile hits the streets of San Francisco. Ramin Talaie, Getty Images

Miles Scott, 5, dressed as Batman. With the help of the Greater Bay Area Make-A-Wish Foundation and the city of San Francisco, Scott, aka Batkid, rescued a woman from cable-car tracks and captured the evil Riddler as he robbed a downtown bank. Miles, who lives in Tulelake, Calif., was diagnosed with leukemia when he was 18 months old. He ended treatments in June and is in remission. Make-A-Wish Greater Bay Area via AP

Crowds gather in front of a former bank vault waiting for Batkid in San Francisco. Ramin Talaie, Getty Images